1. Field of the Invention
The present invention relates generally to improvements in automatic labeling systems and, more particularly, pertains to new and improved systems for applying pressure-sensitive adhesive labels to moving articles.
2. Description of Related Art
In the field of automatic label dispensing and applying systems, it has been the practice to handle the label, which has one face covered with pressure-sensitive adhesive, by the other face which has printing thereon, to both maneuver the label into contact with that portion of an article which is to receive the label, and to attach the label to the article.
Generally speaking, these prior art systems utilize differential air pressure, i.e., vacuum, or a static charge, to hold the label. Once it has been dispensed from its backing material, the label is held by its printed face. Some systems apply the label to the article by an air blast. These are generally known as air blow machines. The problem with these machines is that about 3/4-inch spacing is used between the label and the article, when the label is blown towards the article, resulting in a very loose placement of the label on the article.
Other systems have been developed to try and overcome this shortcoming. They have utilized a combination of the air blow method with a tamp method. Such combination machines utilize an air vacuum to hold the label, physically move the entire label-holding head close to the article, and then blow the label onto the product or article from a closer distance, thereby more accurately placing the label on the article.
Other systems, known strictly as tamp systems, hold the label by a static charge and physically place the label on the product. A variation of the tamp machine is a machine that utilizes a wipe-on method wherein only the edge of the label is touched to the article, and the label is pulled off the holding head as the article moves past. The wipe-on method provides for accurate placement of the label on the article.
However, this system requires that the movement of the article past the label-holding head and the speed of dispensing the label must be precisely controlled. Such controlled systems require stepping motors or clutch-and-brake mechanisms to precisely index the dispensing of the labels in synchronism with the speed of the article. If this is not done, the label will be applied in a wrinkled fashion or tear or deform.